\[\sqrt{\left(\left(2 \cdot n\right) \cdot U\right) \cdot \left(\left(t - 2 \cdot \frac{\ell \cdot \ell}{Om}\right) - \left(n \cdot {\left(\frac{\ell}{Om}\right)}^{2}\right) \cdot \left(U - U*\right)\right)}\]

\sqrt{\left(\left(2 \cdot n\right) \cdot U\right) \cdot \left(\left(t - 2 \cdot \frac{\ell \cdot \ell}{Om}\right) - \left(n \cdot {\left(\frac{\ell}{Om}\right)}^{2}\right) \cdot \left(U - U*\right)\right)}

double f(double n, double U, double t, double l, double Om, double U_) {
        double r175904 = 2.0;
        double r175905 = n;
        double r175906 = r175904 * r175905;
        double r175907 = U;
        double r175908 = r175906 * r175907;
        double r175909 = t;
        double r175910 = l;
        double r175911 = r175910 * r175910;
        double r175912 = Om;
        double r175913 = r175911 / r175912;
        double r175914 = r175904 * r175913;
        double r175915 = r175909 - r175914;
        double r175916 = r175910 / r175912;
        double r175917 = pow(r175916, r175904);
        double r175918 = r175905 * r175917;
        double r175919 = U_;
        double r175920 = r175907 - r175919;
        double r175921 = r175918 * r175920;
        double r175922 = r175915 - r175921;
        double r175923 = r175908 * r175922;
        double r175924 = sqrt(r175923);
        return r175924;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 
(FPCore (n U t l Om U*)
  :name "Toniolo and Linder, Equation (13)"
  :precision binary64
  (sqrt (* (* (* 2 n) U) (- (- t (* 2 (/ (* l l) Om))) (* (* n (pow (/ l Om) 2)) (- U U*))))))

Backtrace

dict-ref: no value for key: 'branch175903 in: '((n . binary64) (U . binary64) (t . binary64) (l . binary64) (Om . binary64) (U* . binary64))		L	C
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	106	4
make-sampler	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	99	0
prepare-points-intervals	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	121	0
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	233	9
sindices->spoints	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	194	0
f33	/opt/racket-7.2/collects/racket/match/compiler.rkt	507	40
get-final-combination	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	369	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28